PM3 study of the [2+3] cycloaddition of 1-nitropropene to methylazide

Two regioisomeric pathways for 1-nitropropene [2 + 3] cycloaddition to methylazide have been evaluated in terms of PM3 calculations. it has been found that four critical structures are located along each of the pathways. Both reactions take place in a concerted manner and their transition states resemble closely the corresponding orientation complexes with a shorter separation and stronger distortion of the reactants. Moreover, it was established that the path leading to 1,5-dimethyl-4-nitrotriazoline is preferred. (C) 1998 Elsevier Science B.V. All rights reserved.